History- purchased 07/2016, 161k. Driven 5k since. Has had recurring P0171/174 codes, often 300+/- miles between codes. Can't find obvious vac leak, but cleaned MAF and drove 1000 miles before next code. Changed leaky valve cover gasket one month ago when last code appeared. 5 days ago, car started, idle was up & down until it warmed up. Drove to office and parked it, same thing happened when I started it and left office. While parking at bank, car sputtered and died. Tried to restart, ran for about 5 seconds and stopped again. Didn't restart. No codes presenting, but P0171/174 codes pending.
Replaced fuel filter/regulator (totally drained fuel lines) & pump; pump primes with ignition at position 2, but no pressure at fuel rail. Turn switch off, then to position 2 again, system primes again, but still no pressure at rail. Tank has 1/2 tank of gas. What am I missing? Thanks very much in advance for any input!
Fuel pump relay?
Was thinking that having power at the pump would mean that relay & fuse were functioning.
Make sure fuel filter was installed in the proper orientation,
fuel flows one way, make sure of the input/output arrows on filter,
and that associated hoses and regulator are not leaking or cracked.
Yep - What Miky said. If you accidentally swapped the two hoses at the rear of the filter, you'll get no fuel to the rail. One is feed, one is return.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
For how long did you crank the engine? It takes a bit of time for fuel to real the fuel rail when you’ve drained the lines.
OOOPS! Your question made me realize what was left out of the story. Research last night revealed how critical a good battery is to the operation of all systems on this car. My battery actually went dead while trying to start the car, so I tried jumping my car from my wife's Jeep Patriot. Didn't work. Obviously I'm due for a new battery. Could that be the culprit? Thanks to all of you for your input!
Apologies to the OP for "jumping" on that, but since I'm still having my own stuttering problems (haven't really had time to look into it last weekend since I tried -and failed- to save my recently installed my power steering pump by replacing the steering gear ): Chris, I did verify that the arrows on the filter where pointed towards the front of the car to make sure it was not mounted backWards, and it is not. But is it somehow possible to swap the left and right sides while the arrows are still pointing forwards? In that case would fuel supply be completely cut or just hampered?
I don't think that would be consistent with the fact that acceleration is sometimes perfectly normal and "healthy" and weak at other times, but I thought I would ask.
Last edited by Breeze1; 10-22-2018 at 01:03 PM.
"If you have integrity, nothing else matters. If you don't have integrity, nothing else matters." Alan K. Simpson.
5spd E46 "3XX": 328i engine, 330i Intake and exhaust, CAI, 323i diff.
No Breeze, this isn't your problem.
John, the battery is very unlikely to be your issue, IF you were able to crank the starter for at least ~20 or 30 seconds TOTAL (never that long in one go, or you'll burn up the starter!)
But note that Marco has an excellent point too....it takes ~10 or 15 seconds of cranking for the fuel pump to fill and pressurize the fuel rail after all the fuel has been purged from the lines.
But on an E46/ late E39, etc, the fuel filter/regulator has two hoses at the rear, side by side, and they CAN accidentally be swapped, which would lead to zero, or inadequate fuel pressure at the rail.
OH, ONE CRUCIAL ITEM:
Where did you buy this fuel pump, and what did it say on the box?
If it did not come in a shiny white box saying VDO or BMW....or if it was not the COMPLETE fuel pump assembly, with the white cover, etc....then that's your mistake.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Thanks, Chris & Marco-
To the point of cranking & empty fuel lines, some further research turned up a couple of folks who said that one needed to prime the pump (not crank) 5-10 times to pressurize the system. I'll try that after I install the new battery this afternoon. Also of note here- after I installed the new pump, I turned the key to position 2, and it primed. I turned off the the ignition and then repeated. 2nd time, no priming noise, nor the third time, but then it primed again on the fourth try. I repeated that entire 4-step cycle 3 times.
As far as swapped fuel lines, is there any way to tell from just looking at them if they are installed correctly?
Fuel pump: The one that wasn't working was a VDO, the one I installed was a Bosch, and it was the entire unit, float included.
Thanks very much for all of your help!
John, the people who told you that you have to "prime the pump without cranking" are full of crap. After all your start / prime attempts, if you don't have fuel pressure, you have the lines crossed. Seriously, I've changed a hundred fuel pumps, and afterwards, I just turn the key to the start position for ~10 seconds max, then rest and repeat, and it will start the second time, if not the first.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Hey, this is late in coming, but thanks so much for the advice. Turns out yes, the hoses were swapped when I replaced the fuel filter. My excuse is that is was done outdoors, in 45 degree weather with drizzling rain, in the dark. (yes, I had a flashlight!) Guess I got in a bit of a hurry. I've also learned to take pictures of everything before disassembly, if it's the first time I've taken it apart, so I can put it back together properly.
glad to hear you were able to fix it!
we all learn from things like this....i'm in the habit now of taking pictures, or creating a mark, or something so i know what went where.
'95 325iS - auto to manual swap done!
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Exactly! I picked up the habit of leaving hints for myself when I was a computer tech. Especially when digital cameras became affordable I would take screenshots before making changes in software, or hardware settings. I'd mark cables with some tape, markers, etc. I can't even recall the number of times doing those kinds of things saved me hours of frustration when working on systems that had acceptable downtimes measured in minutes!
it's also saved me numerous times working on cars...
much like this kind of stuff - it's a habit learned through hard won experience!
'95 325iS - auto to manual swap done!
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